adb = db.getSiblingDB("admin")

adb.auth("root", "example");

adb.createUser({
    "user": "datakit",
    "pwd": "123456",
    "roles": [
      { role: "read", db: "admin" },
      { role: "clusterMonitor", db: "admin" },
      { role: "backup", db: "admin" },
      { role: "read", db: "local" }
    ]
  });
